First melt the butter. In a blender or food processor add the meat, butter, garlic, tomato puree and blend until smooth. If it's too thick add more tomato puree or just little water or chicken stock or olive oil.

Blend it until very smooth. Season with salt and pepper by your liking. Add some herbs by your taste like dried thyme, parsley etc. You can put it in airtight container and it will last couple of days in the fridge.